TORONTO — Nuclear war anywhere on Earth could irrevocably harm the planet’s oceans and worsen the already bleak outlook for coral reefs, according to a new study.
The report, published last month in the journal Geophysical Research Letters, looked at how the oceans would respond if nuclear bombs exploded and sent huge amounts of black carbon into the atmosphere.
“A lot of things would change in the oceans once you dim the lights,” Nicole Lovenduski, the study’s lead author and an associate professor in the Department of Atmospheric and Oceanic Sciences at the University of Colorado at Boulder, said in a statement.
Using complex computer simulations, researchers examined the impact of hypothetical nuclear wars, including a conflict between India and Pakistan. The first effect, researchers say, would be a dip in the acidity of the world’s oceans within a year.
That impact could be significant. Ocean acidity has steadily risen since the start of the industrial revolution and reduced the ocean’s ability to absorb carbon dioxide, thereby weakening its ability to moderate climate change.
Researchers say the slight drop in ocean acidity would be followed by a major shift in the ocean’s chemistry. About three to five years after the bombs exploded, the planet’s oceans would begin sucking up more carbon dioxide from the air.
The influx of CO2 into the water would then reduce aquatic supplies of carbonate – an important building block for oceanic structures such as coral, sea shells, oysters, clams and sea urchins.
“It makes me question whether organisms could adapt to such a change,” Lovenduski said. “We’re already questioning whether they can adapt to the relatively slower process of man-made ocean acidification, and this would happen much more abruptly.”
‘THE IMPACTS ARE HUGE’
Coral reefs cover less than one per cent of the world’s ocean floors but support about 30 per cent of marine life. Global warming and ocean acidification have already taken a toll on the world’s reefs. Last summer, Australia downgraded its outlook for the Great Barrier Reef from “poor” to “very poor.”
According to a 2018 report by the United Nations intergovernmental panel on climate change, 70 to 90 per cent of the world’s coral reefs could vanish if global warming increases 1.5 C.
Nuclear war – no matter what size — would only make the current outlook more bleak, researchers say.
“The impacts are huge,” Lovenduski said. “I hope this study helps us to gain perspective on the fact that even a small-scale nuclear war could have global ramifications.”
The consequences of nuclear war on land are well studied. Researchers have suggested that the smoke from a nuclear war would trigger a “nuclear winter” capable of decimating agriculture, and the World Health Organization has studied the effects of nuclear war on health since 1981.
Researchers say their new study is the first of its kind to consider the impact on the oceans.
DOOMSDAY CLOCK TICKS FORWARD
Last month, the Doomsday Clock – a measure of how close human civilization is to total collapse – was moved up to 100 second before midnight, with midnight representing the end of the world.
The measure was created in 1947 by the Bulletin of the Atomic Scientists in response to the threat of nuclear war between the U.S. and Soviet Union.
“We now face a true emergency — an absolutely unacceptable state of world affairs that has eliminated any margin for error or further delay,” the Bulletin’s President Rachel Bronson said in a statement.
In December, Russian President Vladimir Putin boasted that his country is the first to develop hypersonic weapons capable of carrying nuclear warheads and travelling 10 times faster than the speed of sound.
In the same month, North Korean leader Kim Jong Un said that his country would soon unveil a new strategic weapon.
The United States and Russia have 90 per cent of the world’s nearly 14,000 nuclear warheads, followed by France, China, the United Kingdom, Pakistan, India, Israel and North Korea.